Solving ODE in Python

gistfile1.py

from scipy.integrate import odeint 
from pylab import *  # for plotting commands 
 
def deriv(y,t):  # return derivatives of the array y 
   a = -2.0 
   b = -0.1 
   return array([ y[1], a*y[0]+b*y[1] ]) 
 
time = linspace(0.0,10.0,1000) 
yinit = array([0.0005,0.2])  # initial values 
y = odeint(deriv,yinit,time) 
 
figure() 
plot(time,y[:,0])  # y[:,0] is the first column of y 
xlabel('t') 
ylabel('y') 
show()